This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A computational model was introduced to predict optimal growth rates of E. coli on several carbon substrates including glucose, glycerol, malate, and acetate (1). Experimental testing of the model showed that E. coli grew optimally on all carbon substrates tested except glycerol. E. coli was subject to growth on glycerol over several generations and it evolved to the optimal predicted growth rate. The metabolic genes were sequenced to identify mutations responsible for the optimized growth rates. In total, eleven different point mutations were identified, and eight of the eleven mutations were in the glycerol kinase gene. The mutations were mapped to highly regulated domains of glycerol kinase. The glycerol kinase mutants have been expressed and structural analysis is underway to determine how these mutations caused an increased growth rate of E. coli on glycerol.